Inhofe is ranking Republican on the Senate Armed Services Committee. Hagan also serves on the committee, and is chairwoman of its emerging threats panel. The two teamed up in a bipartisan effort that resulted in both the House and Senate agreeing to prevent tuition assistance from being terminated.

Their letter reminds Hagel that the 2013 government funding bill signed by President Obama on March 27 requires the services to keep providing tuition assistance benefits through the end of September.

Exactly how much money is available is one of the unresolved issues. The language of the Inhofe-Hagan legislation requires the services to fully spend all of the money appropriated for tuition assistance but allowed the amount to be reduced under sequestration. One thing the two senators want to know is how much money each of the services has left.

Defense and service officials have said they are trying to assess how much money is available and how best to spend it before the Army, Air Force and Marine Corps restart their tuition assistance programs. The Navy never stopped its program.

In 2012, tuition assistance paid for 870,000 classes for service members leading to 50,500 degrees, diplomas or certificates, Inhofe and Hagan said. The “impressive” results included 33,300 two-year degrees, 9,600 four-year degrees, 5,800 master’s degrees and 1,800 certificates or licenses, the letter says.

“These are truly extraordinary numbers, which are even more striking since these accomplishments were achieved during a service member’s limited free time,” the letter says.

Given the problems veterans face in finding post-service employment, the senators said they believe tuition assistance “is critical” in transitioning to civilian life.